Catalytic apparatus



March 22, 1932. A. o. JAEGER CATALYTIC APPARATUS Filed Dec. 5. 1927S-Sheets-Sheet l FIG.

anvenloz A/p/zom; 0 Jaeye/ March 22, 1932. A. o. JAEGER CATALYTICAPPARATUS Filed Dec. 5. 1927 s Sheets-Sheet 2 FIG. 6v

March 22, 1932. A. o. JAEGER CATALYTIC APPARATUS Filed Dec. 5. 1927 5Sheets-Sheet 3 A/p/zons 0 Jaeyer INVENTOR. m @g ATTORNEY March 22, 1932.A. o. JAEGER CATALYTIC APPARATUS Filed Dec. 5, 1927 5 sheets shee't 4 INV EN TOR.

ATTORNEY March 1932* A. o. JAEGER CATALYTIC APPARATUS Filed Dec. 5, 19275 Sheets-Sheet 5 A )phons O. Jaeger IN VENT OR ATTORNEY Patented Mar.22, 1932 UNITED STATES PATENT OFFICE.

ALPHONS 0. JAEGER, GRAFTON, PENNSYLVANIA, ASSIGNOR TO THE SELDEN COM-PANY, OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF DELAWARE CATALYTICAPPARATUS Application filed December 5, 1927. Serial No. 237,613.

This invention relates to catalytic apparatus and more particularly toconverters for vapor phase catalytic reactions especially thoserequiring accurate temperature con- Many vapor phase catalytic reactionsrequire a powerful temperature control because of the large amount ofheat evolved in some of the reactions and because it is necessary to 1provide an accurate temperature control in order to maintain reactionconditions for optimum production. The necessity for control isparticularly needed in oxidation reactions such as the oxidation ofsulfur dioxide to sulfur trioxide and many organic compounds tointermediate products. Examples of these reactions areanthracene-containing materials to anthraquinone, toluol or derivativesof toluol to. corresponding benzaldehydes and benzoicacids, benzol tomaleic acid, acenaphtheme to acenaphthaquinone,bisacenaphthylidenedione, naphthaldehydic acid, naphthalic anhydride,and hemimellitic acid, fiuorene to fluorenone, eugenol and isoeugenol tovanillin and vanillic acid, methyl alcohol and methane to formaldehyde,ethyl alcohol to acetic acid, ethylene chlorhydrine to chloracetic acidand the like. Organic oxidations in which impurities are selectivelyburned out 59 or transformed into easily removable substances alsorequire accurate control. Examples of such reactions are thepurification of crude anthracene of phenanthrene by the selectivecatalytic'combustion of carbazol, the purification of crude naphthalene,crude mononuclear aromatic hydrocarbons and crude aliphatic compoundssuch as high sulfur oils and motor fuels. Ammonia from coal tar may alsobe purified by selective oxidation of organic impurities and requires agood temperature control.

In addition -to the strongly exothermic oxidation reactions referred toabove, the apparatus of the present invention may be used with excellenteffect for-other reactions, some of which are not so stronglyexothermic. Thus for example, ammonia can be oxidized to nitrogenoxides, preferably with the omission of uncooled catalystlayers. Thecatazoic acid in converters described for example, nitro compounds maybe cat alytically reduced to the corresponding amines or otherintermediate reduction products. Nitrobenzene, nitrotoluol, nitrophenol,nitronaphthalene, and the like are compounds which can be effectivelyreduced in converters of the present invention. Hydrogenation reactionsare also readily carried out in con verters of the present invention,for example the hydrogenation of benzol to cyclohexane, phenol tocyclohexanol, naphthalene to tetraline and decaline, crotonaldehyde tonormal butyl alcohol, acetaldehyde to ethyl alcohol and the like. I

Various synthetic reactions, such as for example the reduction of oxidesof carbon to methanol, higher alcohols and ketones or synthetic motorfuel mixtures are well adapted for the converters of the presentinvention. The processes may be carried outwith or without pressure.Other synthetic reactions such as the synthesis of ammonia, hydrocyanicacid and the like, may also be carried out in automatic gas cooledconverters according to the present invention.

Other catalytic reactions are of importance, such as the catalytic watergas process, catalytic dehydrogenations, dehydrations, condensations andpolymerizations. The catalytic splitting off of carbon dioxide frompolycarboxylic acids is another reaction for which converters of thepresent invention are well adapted. Thus, for example, phthalicanhydride may be catalytically split to benabove. Composite reactionssuch as the splitting ofi of carboxylic groups from phthalic anhy-'dride in a reducing atmosphere to produce benzaldehyde, benzyl alcohol,and the like, the catalytic splittin of the carboxylic group of phthalidto produce benzyl alcohol and other'composite reactions may effectivelybe carried out in 'convertersof the present invention, it being notedthat endothermic as well as exothermic reactions are practicable. 100

Cracking reactions and destructive hydrogenations such as, for example,destructive hydrogenations of crude phenanthrene, are examples of afurther type for which the apparatus of the present invention is welladapted. In general almost any vapor phase catalytic reaction can becarried out by means of apparatus employing the principles of thepresent invention. i In the past, two general types of converters havebeen used, those cooled by reaction gases and those employing a bath,boiling or nonboiling, in heat exchanging relation to the catalyst. Thepresent invention relates to gas cooled converters. Gas cooledconverters used in the prior art have been of two general types, tubularconverters in which the catalyst is placed in a number of tubessurrounded by the gaseous cooling medium and converters in which layersof catalyst are used, as for example the well known Grillo type ofcontact sulfuric acid converter. Tubular converters give powerfulcooling especially when properly constructed, particularly where tubesof relatively small diameter are used. These converters, however, areexpensive-to build and maintain and require a very large number of gastight joints. Tubular converters are also open to the furtherdisadvantage that it is diflicult to adjust the catalyst resistance togas flow perfectly uniformly in all of the tubes and frequentlynecessitates long and expensive hand filling of the converters. Thecooling also is not fully automatic and fluctuations in reaction speedare apt to upset the temperature control. Nevertheless, hitherto tubularconverters have been considered the best for use in delicate or highlyexothermic reactions or where high loadings are desired.

Layer type converters are cheap to build, present no difiiculty incatalyst filling, and permit a very uniform gas flow throughout thewhole of the catalyst layer. They are, however, practically useless whenhighly exothermicreactions or high loadings are in question or verydelicate temperature control is necessary. The catalyst layers arecooled practically only by the converter wall and by the reaction gasespassing through them and as most catalysts are poor conducare equallyapplicable to endothermic as well as exothermic reactions.

According to the present invention a catalyst layer is used in whichdouble counter current heat exchangers are embedded. These heatexchangers permit the reaction gases to flow first in indirect heateXchang-.

ing relation with the contact mass, then reverse their flow and pass indirect heat exchanging relation with the contact mass, and then after asecond reversal of flow pass through the contact mass. The heat exchangeelements of the present invention consist in nested annuli, each annulushaving one end. open and in one modification one set of annuli fittinginto the other set. The catalyst is placed in the annular spaces definedbetween one set of annuli and the reaction gases enter into one set ofannuli, for example through the annular spaces defined by the other setof annuli. The invention will be clear from the more detaileddescription which follows taken in conjunction with the drawings inwhich Fig. 1 is a vertical cross sectionthrough a converter showing asimple type of converter embodying the principles of the presentinvention;

Figs. 2 and 3 are horizontal sections along the lines of 2-2 and 33 ofFig. 1;

Fig. 4 is a vertical section through a converter of the type shown inFig. 1 but provided with catalyst annuli ,of decreasing thickness fromthe periphery toward the center of the converter in order to providemore powerful cooling of the central portion;

Figs. 5 and 6 are horizontal sections along the lines of 55 and 66 ofFig. 4;

Fig. 7 is a vertical section throu h a converter of the type shown inthe foregoing figures but provided with an orifice plate to vary theamount of gases flowing into the upper annuli;

Figs. 8 and 9 are horizontal sections along the lines of 88 and 9-9 ofFig. 7;

Fig. 10 is a vertical section through a converter of the type shown inFigs. 4 to 6 provided with additional uncooled catalyst layers;

Figs. 11 and 12 are horizontal cross sections along the lines of 1111and 12'12 of Fig. 10;

Fig. 13 is a vertical section of the type shown in Figs. 7 to 9 butprovided with auxiliary means for introducing part of the re actiongases directly into the catalyst;

Figs. 14 and 15 are horizontal cross sections along the lines of 1414and 15-15 of Fig. 13.

The converter shown in Fig. 1 consists in a shell 1, top piece 2, bottompiece 3, catalyst supporting screen 4, reaction gas inlet 5, and outlet6. In the converter are nested con centric annuli 7, having their closedends resting on the screen 4 and open at their upper end. What wouldcorrespond to the central annulus is, of course, a closed-end tube 8.Concentric annuli 9 are nested into the annuli 7 and closed end tube 8with their perforated open ends extending into the annuli 8 The outsideannulus ofeach system consists in open cylindrical L-shaped plates 10and 11 which with the converter wall 1 de'fj;

annular spaces defined between the annuli' 9 including the L-shapedplate 11. In this flow they are in indirect heat exchanging relationwith the catalyst as a moving gas is interposed betweenthe wallsdefining the annular spaces and the catalyst retaining walls. Inreaching the bottom of the annular space the reaction gases pass outthrough the perforations, reverse their flow and pass up in the annularspaces defined between the an-- nuli 9 including the L-shaped plate 12and the annuli 7 including central tube 8. During this reverse flowgases are in direct heat exchanging relation with the catalyst throughthe catalyst retaining walls. On reaching the top of the annuli 7 andcentral tube 8 the gases again reverse their flow and pass downwardlythrough the catalyst and then out through pipe 6. It will be apparentthat the temperature controlling effect of the reaction v gases isexactly proportional to the speed of their flow and as the speed of fiowalso defines the amount of heat generated in the catalyst in the case ofan exothermic reaction or heat absorbed in the case of an endothermicreaction the temperature will remain constant without regard to speed ofreaction gases within wide limits. Bya suitable dimensioning of theannuli the spaces traversed by the reaction gases on their downward flowand particularly on their upward flow can be made as small as desired inorder to maintain a high reaction gas velocity in order to assure highlyeffective heat transfer. In the same way the dimensions and spacing ofthe annuli 7 will determine the thickness of the catalyst annuli and anoptimum thickness of catalyst for any particular reaction or anycatalyst of particular heat conductivity can be obtained. In generalhighly exothermic re in order to provide for most eifective heattransfer.

While the cooling is substantially completely automatic and does notvary with variations in reaction gas speed, it should be noted that thisapplies only to the cooling effected by the reaction gases themselves.Cooling which is effected by radiation or conduction from the convertershell does not vary with the gas velocity. In order to compensate forthis additional cooling which, of course, is most eifectivein peripheralcata- 1 st zones it is desirable in some cases to vary t 1e thickness ofthe catalyst annuli, decreasing the thickness from the periphery towardthe center of the converter so that the cooling efficiency and heatevolved is varied to compensate for converter 'shell cooling. This typeof converter is shown in Figs. 4 to 6 which are identical in design withFigs. 1

will result in a decrease in the factor of converter shell cooling.However, it is not practicable to provide complete insulation and forcertain delicate or highly exothermic reactions it is thereforedesirable to utilize a progressively varying catalyst thickness as shownin. Figs. 4 to 6.

Figs. 7 and 8 illustrate a converter of the general design shownin Figs.4 to 6 but pro-' vided with a perforated plate 15 placed above the upperannuli andprovided with concentric circles of orifices 16 illustratingthat the annular spaces defined between the upper annuli, by a suitableadjustment of the size and number of perforations the proportion ofgases flowing through the different annular spaces can be varied and bythis means the amount of cooling can also be varied to compensate forthe cooling effect of the converter shell. Figs. 7 and 8 also show avariation in thickness of catalyst an'nuli as shown in Figs 4 to 6 butcan, of course, where desirable .be designed with catalyst annuli ofconstant thickness as in Figs. 1 to 3.

Figs. 10 to 12 illustrate'a converter of the design shown in Figs. 4 to6 but is provided with two uncooled catalyst layers 17 and 18 supportedby screens 19 and 20 and provided 'with fillingtubes 21 and 22 andemptying tubes .23 and 2-1. Baflie plates 31 and 32 are-also interposedbetween the annular catalyst layers and the first uncooled layer andbetween the latter and the second uncooled layer. The operation of theconverter is the same as that shown in Figs. 5 and 6 but may be usedwhere it is desirable to run the automatic gas cooled layers at loadingsin excess of those permitting high percentage yields,

the partly reacted gases then being caused to contact with uncooledlayers to effect the last few percent of conversion which, of course,does not generate much heat in the case of exothermic reaction or doesnot require much heat in the case of endothermic reaction. The bafileplates 31 and 32 provided enhance mixing of the partly reacted gases andalso tend to throw them out toward the converter shell where they aresubjected to cooling or heatin thereby.

The arrangement shown in Figs. 10 to 12 is also very suitable forcomposite reactions which take place in two'stages, particularly wherethe first stage is strongly exothermic or requires a particularlydelicate control. The catalysts in the different layers may be differentand even in the case of a single reaction it is frequently desirable tovary the nature of the catalyst in the different layers, thus, forexample, the later layers may advantageously be provided withprogressively stronger catalysts. The catalyst in the automatically gascooled catalyst layers may also vary in strength in the direction of thegas flow and this feature may, of course, also be applied to theconverters shownv in the other gures.

Figs. 13 to 15 illustrate a converter of the general type shown in Fig.1 but provided with means for introducing some reaction gas directlyinto the catalyst without passing into the counter current heatexchangers. For this purpose the converter is provided with a perforatedplate 25 placed above the annuli 9 and forming therewith a chamber orspace 26 into which the reaction gas pipe 5 leads. The perforated plate15 is connected to the tops of the annuli 9 and the L-plate 11 by meansof short tubes 27. An auxiliary gasintroducing pipe 28 controlled by avalve 29 is mounted into the top piece 2 of the converter and bafiles 30are placed between the top piece 2 and the perforated plate 25. v

In operation the reaction gases passing in through'the pipe 5 flowdownthrough the double counter heat exchangers precisely as in theforegoingfigures. Additional reaction gas coming in through the pipe 28flows through the pipes 27 directly to the catalyst without passing tothe heat exchangers. This auxiliary gas maybe used to adjust thetemperature of the gases passing into the catalyst or it may be used inan emergency to control excessive reaction violence. Obviously, ofcourse, the other features shown in the foregoing figures, such asvariation of the catalyst thickness, provision of uncooled catalystlayers, and the use of tubes in place of one set of annuli, as shown inFigs. 7 to 9, may be combined with auxiliary gas introduction shown inFigs. 13 to 15. Other modifications within the scope of'the inventionwill readily occur to a skilled engineer and are included in theinvention. The drawings are purely diagrammatic and, of course, allnecessary accessories and proper structural features will be chosen bythe engineer.

In the claims, the expression direct heat exchanging relation is used todefine a heat exchanging relation in which there is a direct flow ofheat, such as that through a solid wall, as opposed to the expressionindirect heat exchanging relation which covers a sidered as the top asthe converter may be readily reversed in the manner shown in Fig. 6 ofmy copending application Serial No. 327,853, filed December 22, 1928.

The structural details of the annular double countercurrent heatexchange converter are shown in Figs. 7 and 8 of my prior Patent No.1,660,511, dated February 28, 1928.

What is claimed as new is:

1. A converter comprising a catalyst chamber, a set of concentric annuliwhich are open at one end and closed at the other arranged therein withthe open ends in the same direction, the central annulus being a tube,catalyst in the spaces defined between said annuli, and means forcausing reaction gases to pass from the open to the closed ends of theannuli, then to reverse their flow within the annuli and pass from theclosed to the open ends thereof in direct heat exchanging relation withthe catalyst and with the incoming gases.

2. A. converter comprising a catalyst chamber, a set of concentricannuli which are open at one end and closed at the other arrangedtherein with the open ends in the same direction, the central annulusbeing a tube, catalyst in the spaces defined between said annuli, andmeans for causing reaction gases to pass from the open to the closedends of the annuli, then to reverse their flow within the annuli andpass from the closed to the openends thereof in direct heat exchangingrelation with the catalyst and with the incoming gases, said meanscomprising similar concentric annuli having one end closed and the otheropen, with their open ends nesting into the first mentioned annuli andcentral tubes, the closed tops of said nesting annuli defining with theconverter shell a chamber, and means for introducing reaction gases intosaid chamber.

3. An apparatus according to claim 1 in which the thickness of thecatalyst annuli decreases from the periphery of the converter toward thecenter.

4:. A. converter according to claim 2 in which the thickness of thecatal st annuli decreases from the periphery 0 the converter toward thecenter.

5. A converter according to claim 1 in which uncooled catalyst layersare provided below the catalyst annuli. v

6. A converter according to claim 1 in which means are provided fordirectly introducing a portion of the reaction gases into v m thecatalyst without passing through the

